I found this searching eBay and it is a new sample that has not been identified before.
I took this sample to PCGS at the Long Beach show to see if PCGS has anyone that remembers producing it. They do agree that it was PCGS produced.
It is a rattler sample with the collar on it like the next generation slab.
This now makes me believe that samples with coin number 05120 were the first samples to be produced (after all zeros). and the correct coin number matching the date and MM were produced at a later time but still during the rattler generation.

David did a nice write up in his sample news letter.

here is a link and it is in "Sample Slab Update Newsletter 14 - 2016 10.pdf" You will need to download it.